Why do "worn-out textbooks" affect Miss Crocker, Little Man and Cassie's mother differently?

Miiss Crocker is appreciative of the old textbooks. Mama finds them demeaning, but she does so quietly and she fixes them. Little Man is completely insulted once he realizes they are used....... dirty.

Little Man knew this too. His lips parted slightly as he took his hands from the book. He quivered, but he did not take his eyes from Miss Crocker. “I—I said may I have another book please, ma’am,” he squeaked. “That one’s dirty.”

Mama did not answer. She had trimmed the paper to the size of the books and was now dipping a gray-looking glue from the brown bottle onto the inside cover of one of the books. Then she took the paper and placed it over the glue.